There are a few reasons why the stereo varitone circuit is silly, and then three extrasilly reasons when you attempt to combine them to mono.
Firstly the obvious out of phase issue when pickups are combined, this can be corrected by flipping the magnet in either pickup, okay some people like it out of phase, but most don't.
Second, the 500k volume pots are wired right at the end of the signal path as they go to the output jack, when you jumper these together to mono, either in the guitar or via any type of Y cord or jumper box, they interact with each other and both volumes affect both pickups regardless of the pickup selection, the mono varitone and 335 are not wired this way, they have the volume pots as the first component the pickups go to, before the selector switch, and they remain independent unless both pickups are selected.
Thirdly and most important, as a result of the volume arrangement above, the 500k pots are effectively now 250k as they are now in parallel, and this is the 'tone suck' that is experienced when doing the mono jumpering. You may know that folks take the 300k pots out of early 80s dot reissue 335s to replace them with 500ks, similar scene, but worse.
Added to this, when the varitone is engaged, each pickups signal goes through a 100k resistor on the way thru the varitone to the volume pots, further inhibiting signal.
I recommend anyone interested in abandoning this arrangement, to try a new harness made up in this circuit I have seen posted here before, with one further mod http://storage.canalblog.com/70/58/274546/17141044.gif
This is the mono varitone, based on the 335 style arrangement of volume and tone pots, the mod illustrated in here is that the switch used is a 2-pole 6 position rotary switch, with the second pole used to activate a true bypass for position 1. This type of switch is easy to get and so are the capacitors used, and you will reuse one of the two existing chokes. My only one further suggestion is to leave out the 10meg resistors entirely.
Firstly the obvious out of phase issue when pickups are combined, this can be corrected by flipping the magnet in either pickup, okay some people like it out of phase, but most don't.
Second, the 500k volume pots are wired right at the end of the signal path as they go to the output jack, when you jumper these together to mono, either in the guitar or via any type of Y cord or jumper box, they interact with each other and both volumes affect both pickups regardless of the pickup selection, the mono varitone and 335 are not wired this way, they have the volume pots as the first component the pickups go to, before the selector switch, and they remain independent unless both pickups are selected.
Thirdly and most important, as a result of the volume arrangement above, the 500k pots are effectively now 250k as they are now in parallel, and this is the 'tone suck' that is experienced when doing the mono jumpering. You may know that folks take the 300k pots out of early 80s dot reissue 335s to replace them with 500ks, similar scene, but worse.
Added to this, when the varitone is engaged, each pickups signal goes through a 100k resistor on the way thru the varitone to the volume pots, further inhibiting signal.
I recommend anyone interested in abandoning this arrangement, to try a new harness made up in this circuit I have seen posted here before, with one further mod http://storage.canalblog.com/70/58/274546/17141044.gif
This is the mono varitone, based on the 335 style arrangement of volume and tone pots, the mod illustrated in here is that the switch used is a 2-pole 6 position rotary switch, with the second pole used to activate a true bypass for position 1. This type of switch is easy to get and so are the capacitors used, and you will reuse one of the two existing chokes. My only one further suggestion is to leave out the 10meg resistors entirely.